CN101877477A

CN101877477A - Leakage protection switch for preventing three-phase power circuit from generating high voltage

Info

Publication number: CN101877477A
Application number: CN2009103020754A
Authority: CN
Inventors: 杨树昌
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-05-01
Filing date: 2009-05-01
Publication date: 2010-11-03

Abstract

The invention relates to a leakage protection switch for preventing a three-phase power circuit from generating high voltage. The leakage protection switch comprises a leakage protection circuit, a zero down protection circuit and a tripping executing circuit, wherein a zero sequence current mutual inductor B1 and a drive circuit DL are used for forming a leakage detection drive circuit; the zero down protection circuit consists of a high-impedance solid-state relay (HZ-SSR); and the tripping executing circuit is connected with an electromagnetic tripping coil L through a power switch K1via a mechanical interlock. When one phase or two phases (comprising a zero line) of the input end of the power switch is a break line, the rest phase still can guarantee the leakage protection circuit to normally supply power and ensure that the leakage protection circuit normally works all the same; and when the zero line of the input end of the power switch K1 is broken off, the power can be cut off in time so as to prevent harms caused by the high voltage of three-phase power due to zero line lack to the human body and electric equipment and achieve the purpose of preventing the three-phase power line from generating high voltage entrance.

Description

Prevent that three-phase power circuit from producing the earth leakage circuit-breaker of high pressure

Technical field

The present invention relates to the urgent protection switch device of a kind of low pressure three phase mains circuit, relate in particular to a kind of earth leakage circuit-breaker that prevents three-phase power circuit generation high pressure that a kind of three-phase and four-line or five-wire system low-tension supply circuit also can shield when phase shortage, disconnected zero line.

Background technology

At present, China's general industry and civilian low-tension supply standard are three-phase and four-line or five-wire system, promptly A phase (or live wire L1), B phase (or live wire L2), C phase (or live wire L3), the N neutral line (or zero line N), add a protective earthing line PE again.Be connected with three-phase (ABC+N+PE) electrical appliance or single-phase (a live wire L+N+PE) electrical appliance by protector, controller (switch, circuit breaker etc.), power lead, protective earthing line PE is connected with power distribution cabinet, device housings usually.Because power line, protector, controller and electric equipment etc. are worked in being vulnerable to air erosion, oxidation, humidity, dust, surge, overvoltage, environment such as under-voltage for a long time; the electrical pickoff of protector or controller is ablated or loose contact; faults such as lead and binding post are loosening or blow; cause power supply phase line or zero line break, promptly produce the three phase mains phase shortage and lack zero phenomenon.

The harm of three phase mains phase shortage, scarce zero failure:

(1), in the three-phase imbalance load, neutral point (zero line) N is 0V to ground wire PE normal voltage, neutral point (zero line) N is 220V to live wire ABC normal voltage, when the zero line N of power end disconnects, be that three phase mains is when lacking zero, the zero line N of broken string part raises after with the power supply dividing potential drop by load, making the load two ends bear voltage U raises rapidly, the operate as normal rated voltage alternating current 220V scope that has surpassed common single-phase electrical equipment widely, and make the electricity consumption equipment burnout, the overwhelming majority is a single phase poaer supply electrical equipment in civil electric appliance especially, so it is bigger to the harm that huge numbers of families cause that power supply lacks zero failure, be commonly called as " high pressure house lead in ", this kind phenomenon happens occasionally, and by network retrieval and market survey, does not also have the product and the method for disclosed a kind of preventing " high pressure house lead in ".

(2), the common ground of present earth leakage circuit-breaker is; its accessory power supply adopts single phase alternating current (A.C.) 220V (L+N) or two cross streams 380V power supply; if chance encounter is used as a phase or a neutral line break dead electricity of accessory power supply; and other phase lines still continue power supply; at this moment as the electric leakage accident takes place in supply line; earth leakage circuit-breaker can not play urgent earth leakage protective effect with malfunctioning.

Summary of the invention

At the blank that exists in the prior art; the present invention aim to provide a kind of can be in three-phase and four-line or five-wire system power circuit; when a phase or two-phase (comprising zero line) broken string wherein; all can make earth leakage protective operate as normal in the same old way; neutral line break that perhaps ought be wherein; when making three phase mains produce high pressure; can in time detect and cut off the electricity supply; prevent the earth leakage protective device of three phase mains circuit " high pressure house lead in "; prevent that promptly three-phase power circuit from producing the earth leakage circuit-breaker of high pressure, is called for short protection switch.

To achieve these goals, the present invention is by the following technical solutions:

A kind of earth leakage circuit-breaker of three-phase power circuit generation high pressure that prevents is made up of leakage protection circuit, disconnected zero protective circuit and dropout executive circuit three parts; protection switch of the present invention have five input A, B, C, N, PE respectively with the A of power supply mutually, B phase, C phase, zero line N, protective earthing line PE be connected, four output L1, L2, L3, N1 are connected with the load power consumption equipment respectively.It is characterized in that:

Described leakage protection circuit is formed the leak(age) test circuit by test switch K2 and resistance R 3, and zero sequence current mutual inductor B1 and driving amplifying circuit DL form the detection of electrical leakage drive circuit, and common combination forms.

Described disconnected zero protective circuit, HZ-SSR forms by the high impedance solid-state relay, and (1) pin of high impedance solid-state relay HZ-SSR is connected with the X point of the zero line N1 that needs to detect, and (3) pin is connected with the Y point, and (2,4) pin is connected with protective earthing line PE.

Described dropout executive circuit is connected by mechanical chain with electromagnetic trip coil L by mains switch K1, and output L1, the L2 of mains switch K1, L3 are connected with electromagnetic trip coil L behind diode D1, D2, D3 three phase half wave rectification.

The technological progress that the present invention obtains:

(1), the present invention has when the input zero line wherein of mains switch K1 disconnects, can in time cut off the electricity supply, prevent that three phase mains from producing the harm that high pressure causes personal and power consumption equipment owing to lacking zero, realizes preventing that the three phase mains circuit from producing the purpose of " high pressure house lead in ".

(2), the present invention have when the input of mains switch wherein one mutually or two-phase (comprising zero line) broken string, as long as the normal power supply of being on good terms wherein just can make leakage protection circuit operate as normal in the same old way.

(3), disconnected zero protective circuit of the present invention is made up of the high impedance solid-state relay, has very high input impedance, in the M ohm level, is equivalent to open a way in less than the 500V circuit at alternating current 220V, 380V and direct current, can ignore to the influence of circuit.

Description of drawings

The present invention shown in Figure 1 prevents that three-phase power circuit from producing the circuit principle structure figure of the earth leakage circuit-breaker of high pressure.

The present invention shown in Figure 2 prevents that three-phase power circuit from producing the circuit principle structure figure of the earth leakage circuit-breaker of high pressure for second kind.

The present invention shown in Figure 3 does not produce the circuit principle structure figure of the protection switch of high pressure with the three-phase power circuit that prevents of creepage protection function.

Facad structure schematic diagram of the present invention shown in Figure 4.

Side-looking structural representation of the present invention shown in Figure 5.

Claims

1. an earth leakage circuit-breaker that prevents three-phase power circuit generation high pressure is made up of leakage protection circuit, disconnected zero protective circuit and dropout executive circuit three parts; the present invention has five inputs (A, B, C, N, PE) to be connected with (A mutually, B phase, C phase, zero line N, protective earthing line PE) of power supply respectively, and four outputs (L1, L2, L3, N1) are connected with the load power consumption equipment respectively.

2. a kind of three-phase power circuit that prevents as claimed in claim 1 produces the earth leakage circuit-breaker of high pressure; it is characterized in that: described leakage protection circuit; form the leak(age) test circuit by test switch (K2) and resistance (R3), zero sequence current mutual inductor (B1) and drive circuit (DL) are formed.

3. a kind of three-phase power circuit that prevents as claimed in claim 1 produces the earth leakage circuit-breaker of high pressure; it is characterized in that: described disconnected zero protective circuit is made up of high impedance solid-state relay HZ-SSR; (1) pin of high impedance solid-state relay HZ-SSR is connected with the X point of the zero line (N1) that needs to detect; (3) pin is connected with the Y point, and (2,4) pin is connected with protective earthing line PE.

4. a kind of three-phase power circuit that prevents as claimed in claim 1 produces the earth leakage circuit-breaker of high pressure; it is characterized in that: described dropout executive circuit is connected by mechanical chain with electromagnetic trip coil (L) by mains switch (K1), and the output of mains switch (K1) (L1, L2, L3) is connected with electromagnetic trip coil (L) behind diode (D1, D2, D3) three phase half wave rectification.

5. a kind of three-phase power circuit that prevents as claimed in claim 1 produces the earth leakage circuit-breaker of high pressure, and it is characterized in that: mains switch (K1) is 3 or 4 killer switches.